GH18 domain of CTS3 (chitinase 3), an uncharacterized protein from the human fungal pathogen Coccidioides posadasii. CTS3 has a chitinase-like glycosyl hydrolase family 18 (GH18) domain; and has homologs in bacteria as well as fungi.
The GH18 (glycosyl hydrolase, family 18) type II chitinases hydrolyze chitin, an abundant polymer of beta-1,4-linked N-acetylglucosamine (GlcNAc) which is a major component of the cell wall of fungi and the exoskeleton of arthropods. Chitinases have been identified in viruses, bacteria, fungi, protozoan parasites, insects, and plants. The structure of the GH18 domain is an eight-stranded beta/alpha barrel with a pronounced active-site cleft at the C-terminal end of the beta-barrel. The GH18 family includes chitotriosidase, chitobiase, hevamine, zymocin-alpha, narbonin, SI-CLP (stabilin-1 interacting chitinase-like protein), IDGF (imaginal disc growth factor), CFLE (cortical fragment-lytic enzyme) spore hydrolase, the type III and type V plant chitinases, the endo-beta-N-acetylglucosaminidases, and the chitolectins. The GH85 (glycosyl hydrolase, family 85) ENGases (endo-beta-N-acetylglucosaminidases) are closely related to the GH18 chitinases and are included in this alignment model.
UBA domain found in Saccharomyces cerevisiae DNA-damage response protein Ddi1 and similar proteins. Ddi1, also called v-SNARE-master 1 (Vsm1), is a ubiquitin receptor involved in regulation of the cell cycle and late secretory pathway in Saccharomyces cerevisiae. It functions as a ubiquitin association domain (UBA)- ubiquitin-like-domain (UBL) shuttle protein that is required for the proteasome to enable ubiquitin-dependent degradation of its ligands. For instance, Ddi1 plays an essential role in the final stages of proteasomal degradation of Ho endonuclease and of its cognate FBP, Ufo1. Moreover, Ddi1 and its associated protein Rad23p play a cooperative role as negative regulators in yeast PHO pathway. Ddi1 contains an N-terminal UBL domain and a C-terminal UBA domain. It also harbors a central retroviral aspartyl-protease-like domain (RVP) which may be important in cell-cycle control. At this point, Ddi1 may function proteolytically during regulated protein turnover in the cell. This family also includes mammalian regulatory solute carrier protein family 1 member 1 (RSC1A1), also called transporter regulator RS1 (RS1) which mediates transcriptional and post-transcriptional regulation of Na(+)-D-glucose cotransporter SGLT1.
UBA2 domain found in Schizosaccharomyces pombe ubiquitin carboxyl-terminal hydrolase 14 (spUBP14) and similar proteins. spUBP14, also called deubiquitinating enzyme 14, UBA domain-containing protein 2, ubiquitin thioesterase 14, or ubiquitin-specific-processing protease 14, functions as a deubiquitinating enzyme that is involved in protein degradation in fission yeast. Members in this family contain two tandem ubiquitin-association (UBA) domains. This model corresponds to the UBA2 domain.
Structure of chitinase, ChiC, from Aspergillus fumigatus. [Aspergillus fumigatus Af293],2Y8V_B Structure of chitinase, ChiC, from Aspergillus fumigatus. [Aspergillus fumigatus Af293],2Y8V_C Structure of chitinase, ChiC, from Aspergillus fumigatus. [Aspergillus fumigatus Af293],2Y8V_D Structure of chitinase, ChiC, from Aspergillus fumigatus. [Aspergillus fumigatus Af293]